This invention relates to a collet retainer and, more particularly, to a collet retainer in which a collet may be disposed at any rotatable position relative to the collet retainer in which it is rotatably supported and retained against movement.
Collets are employed to hold workpieces for machining operations, for example. One means of presently holding collets against rotation is by a locking pin extending into a longitudinal slot in threads in the outer surface of the collet. Thus, the collet may not be disposed in any rotatable position but only at one specific position through 360xc2x0 at which the locking pin can extend into the longitudinal slot in the threads in the outer surface of the collet.
A disadvantage of this collet locking arrangement is that a user may fail to dispose the locking pin in the longitudinal slot in the threads in the outer surface of the collet. This can damage the threads whereby the collet may no longer be usable. With relatively large size collets, this is a relatively expensive cost.
Another disadvantage of this collet locking arrangement is that a fixture, which has a plurality of collets, cannot have the collets disposed too close together. This is because of the need for access to each of the locking pins extending into one of the longitudinal slots in the threads in the outer surface of one of the collets. Therefore, when it is desired to have a number of the collets holding the same workpieces for the same machining operation, for example, the need for accessibility to the locking pin restricts the number of collets in a given support area on a fixture. Thus, maximum utilization of the support area is not obtained.
When it is desired to change the orientation of a non-round workpiece relative to the fixture in which the collet is rotatably supported, the collet must be rotated. As a result, the longitudinal slot in the collet could be positioned so that the locking pin cannot align with the longitudinal slot whereby the desired orientation of the non-round workpiece relative to the fixture is not possible.
The collet retainer of the present invention satisfactorily overcomes the foregoing disadvantages of the collet retainers in which each of the locking pins extends into one of the longitudinal slots in the threads in the outer surface of one of the collets. The collet retainer of the present invention does not require a longitudinal slot in the threads in the outer surface of the collet. This eliminates the possibility of damage to the threads in the outer surface of the collet by the locking pin when there is not alignment of the longitudinal slot with the location of the locking pin.
The collet retainer of the present invention utilizes a locking nut for cooperating with the threads in the outer surface of the collet to lock the collet against rotation. This allows the collet to be disposed at any rotatable position relative to its longitudinal axis. This enables more precise adjustment than is presently available for the orientation of the non-round workpiece, for example. Even with only a slight difference in the adjustment of the orientation of the non-round workpiece due to the pitch of the threads in the outer surface of the collet, this can result in the orientation of the non-round workpiece not being at the desired position when employing the collet with the longitudinal slot in the threads in the outer surface of the collet to receive the locking pin.
When used in a fixture, the collet retainers of the present invention do not require the same total support area as the same number of the previously discussed collet retainers. This is because there is no need for accessibility on any side of the fixture as is necessary when using the collet retainer having the locking pin for disposition in the longitudinal slot in the threads in the outer surface of the collet.
Instead, the collet is locked against rotation in the collet retainer of the present invention through turning a collet locking screw. The collet locking screw for each collet is accessible from the top of the fixture. Thus, there is no need for any lateral spacing in the fixture between the various collet retainers of the present invention as has previously been necessary.
An object of this invention is to provide a collet retainer for retaining a collet at any desired rotatable position within the collet retainer.
Another object of this invention is to provide collet retainers in a fixture having no requirement for accessibility from a side to lock each collet against rotation.